Sheriff Buck Marston, Sr. and his wife are killed after he defies the bandit known as the Wolf. Years later, Marston's son Buck, reared by kindly rancher Jack Remington, steps into his father's shoes and becomes sheriff, vowing vengeance for the death of his family. Eventually only the Wolf and his son remain, and although Buck finally succeeds in capturing the Wolf, the Whelp comes to his father's rescue and frees him. Meanwhile, when Remington overhears his younger daughter Dolly confide in her sister Barbara, Buck's fiancée, that she has been having an affair with the Whelp, Remington misunderstands and, assuming that Barbara has been betrayed, insists that she marry the outlaw. Returning from his pursuit of the Wolf, Buck learns of Barbara's fate and speeds to the Wolf's den where the Whelp has taken his bride. Buck saves Barbara, kills the outlaws and thus succeeds in winning both revenge and his sweetheart.